OBJECTIVETo investigate the effect of alantolactone on perliferation and apoptosis of multiple myeloma (MM) RPMI-8226 cells, and to explore its possible mechism in vitro and in vivo.

METHODSThe RPMI-8226 cells were treated with alantolactone (1, 2.5, 5, 7.5 and 10 µmol/L) for 48 h, cell viability was detected by CCK-8 assay and the value of IC50 was calculated; The RPMI-8226 cells were treated with alantolactone (2.5, 5 and 7.5 µmol/L) for 48 h, the apoptotic rate was detected by flow cytmetry with Annexin V/PI staining; the expression level of cleaved caspase-3 and phosphorylation of ERK were measured by Western blot; the nude mice was used to further confirm the proapoptotic effect of alantolactone on MM cells in vivo.

RESULTSThe alantolactone inhibited RPMI-8226 cell viability remarkably with a dose-dependent manner; the IC50 value of RPMI-8226 cells at 48 h was 4.32 ± 0.15 µmol/L; the apoptotic rate increased observably with a dose-dependent manner; the levels of cleaved-caspase-3 increased and the phosphorylation of ERK decreased significantly; as compared to control, the volum of tumor was much smaller, the expression levels of Ki67 and p-ERK decreased.

CONCLUSIONThe alantolactone can efficiently inhibit the proliferation and induce the apoptosis of multiple myeloma RPMI-8226 cells in vitro and in vivo through inhibiting the activation of ERK signal pathway.